What is the consequence of not completing a required proficiency check on time?

The consequence of not completing a required proficiency check on time is the loss of flight privileges. This is rooted in regulatory standards that ensure pilots maintain a certain level of proficiency and safety. Flight privileges are contingent upon meeting the requirements set forth by the Federal Aviation Administration (FAA), and failing to complete proficiency checks as mandated can lead to an invalidated certification or rating. Consequently, pilots may not legally operate an aircraft until they have successfully completed the required proficiency check.

While increased insurance costs, mandatory retraining, and fines from the FAA might occur in hypothetical scenarios, they are not direct consequences of failing to complete a proficiency check on time. The fundamental issue centers on maintaining valid flight privileges, which hinges on adherence to these crucial checks.